Belt Drive help

1. The problem statement, all variables and given/known data
After a certain amount of running, there is likely to be changes in the values of the engineering parameters of the system in section (a). One of these is the friction coefficient, Carry out the activity with calculations to find out the effect on power transmission if the friction coefficient reduces to 0.2 from 0.25: how can the original maximum power value be restored?

Ive worked out the power for both 0.25 and 0.2

The power is the same but i had to change F1 to 1165N, but the maximum tension is the belt can only exceed 1000N how could i get the same powers? would i have to use a belt tension device?

1a - has the calculations for working out 0.25 as the coefficient and the original question
1c - has me working out for 0.2 as the coefficient, also shows how to gain the same power with 1165N as F1

No, it should be possible to calculate θ1 and θ2. I'm not sure about the name of the law to be used ( I'm not a mechanical engineer ), but there is a law by which max torque can be calculated as a function of tension, angle and friction coefficient.

No, it should be possible to calculate θ1 and θ2. I'm not sure about the name of the law to be used ( I'm not a mechanical engineer ), but there is a law by which max torque can be calculated as a function of tension, angle and friction coefficient.

So once ive found the angles, i just sub them in when working out the lap angles? for example: